Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/Stewart/Riddell/tmp/Tune-4757-_.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-4464-Tune-4757-_.ps) >>/Users/jc/w/tmp/Tune-4464-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/Stewart/Riddell/tmp/Tune-4757-_.abc

Error exit status 256; here are some files to check:
[P=tuneget V=1/1 B=0 scale=0.55 512x512 PNG]
filesizedescription
Coll_44640.log 465409 Log file, useful mostly for debugging
Coll_44642.log 450011 Log file, useful mostly for debugging
Coll_44645.log 444410 Log file, useful mostly for debugging
Tune-4464-Tune-4757-_.abc 163 ABC music file with the extracted tune(s)
Tune-4464-Tune-4757-_.ps 6 PostScript
Tune-4464-Tune-4757-_.txt 163 Plain-text file with the extracted tune(s)
Tune-4464-get.log 4175 Log file, useful mostly for debugging
Tune-44641-get.log 1541 Log file, useful mostly for debugging
These files should be available for 24 hours.